Self-seating device for drilling bits



May 19, 1931. E SMWH4 1,805,678

SELF SEATING DEVICE FOR DRILLING IYTS Filed Sept.. 27, 1926 myENToR 54' ,vwl WMJ/A '71: 'ATTORNEYS Parenteel May A19, i931 rss " frisur vri-"ie i EcfdLrJsroN sr/HTH, orfnreieironnoir, new rome ssroitonmo ntieLEsfronnrtrLLINo coRronA'rIor-T, ornovrrt, DELAWARE, A oortroaefrron or DELAWARE o sanr-snerrnennvrcn son hermine nire' i Application mea september 27,1926.' semina. 15mm This invention relates( to 'apparatusfor earth-boring and particularly to apparatus for drilling` Wells for oihgas, Water and the lil-re. The invention more especially concerns earth-boring apparat-us of the rotary type in which the cutting orabrading of the material being drilled through,such,lfor'example, as rock or mineral, is done by means of a rotary toolv. l l

The object of the invention is to improve the construction of earth-boring apparatus of this character to the end that either small or large holesmay bey drilled. with a greater degree of' convenience, more expeditiously and at less cost than hitherto. f

In operating rotary drilling tools considerable dilticultyhas heretofore been experienced because of the refusalv of the drilling bit tocut. smoothlyjunder certain conditions. This difficulty has been encountered With steel bits 'of the so-called fish-tail type, as Well as withy steel bits having a relatively large number of cutting edges7 and with abrasive bit-s. The refusal to cut smoothly has been 7 evidenced by a phenomenon known as chattering Whichis very destructive to both the 'bits and the `drivingmechanism. In carry'- ing` ont certainirather extensive investigations iu the d rilling of oil and Water Wells by means ofthe apparatus set forth in my copending application, Serial No. 712,197, filed May'll), A19%` l have discovered the reasons for this chattering', and have provided means or mech- Vanism for eliminating' it, Whichis the subject matter of the present application. i

.My prior application just referred to relates to a device for connectin-ga drillingtool or hit made ofabrasivelmaterial, such7 for instance, asA carborundum, with a drill stem i or drive pipe, by' means of 'which the feeding pressureon the abrasive bitcan be readily controlled, inasmuch as the Weight of the drive pipe itself is removed from the bit, and the feeding pressure is supplied by applying a predetermined force to the connecting device bymeansof Weights of predetermined value or by other suitable means.- Y i ln drilling by means of the existing rotary methods, the bit is firmly secured to the drill stemrlsoithatitvmoves as an integral part oi',

that stem.- vl/Vhen drilling veryl shallow 'holes-that is holes in Which thelength of tl e drill stem is only a few inches lbeyond its last fixed lateral support-the airis of rotation of the drill essentially coincides with the axis of the hole andthe surface ofthe face of the bit coincides with the surface to be'cut;` AsA Y thedepth ofthe hole increases andfthedrill raising the opposite side out' of contactwith the'bottoin. rl/ilientlie bit Y'is s0. cantechy instead of rotatinpuabout itscentral axis,` Vit changes its center of rotation and tends to turn about its ypoint of support on the rim. The diameter ofthe. hole even vin the imme` diate vicinity of the bit -is,-hoWever,A some- What larger than the diameterof the bit and rotation can therefore take place for'aii instantandto `a limited extent yabout the Vnew center; The new rotation is stopped as soon asfthe bit strikes the sider ofthe *hole and rotav` tion is then transferred baclr tothe axis of the bit for an instant While the point of si A port at the riin jumpsfoi-Ward to a nen7 point of contact and supporti The continued repe tit-ion of this procedure; is,`v lbelieveyiyha't producesthe chattering of thebit.

, As the depthof the 'hole increases land considerable drill stem is added,` another factor comes infyvhi'ch` produces a deviation of 'the' axis of the drill l'and-drillstem frointhat' of the holebeing` vdrilled and which augments the 'tendencyto chatten 4lninost dri-lling.

- operations pressure' is put upon the Tbiteither,

leanuoveruntil it obtainslateral:support from' the wall of the hole. When pressure is put upon the bit, the lower end of the stem leans over to the wall causing the axis of the drill stem to deviate from the axis of the hole, and chattering is produced.

In accordance with my present invention, the undesirable effect of the leaning or canting of the. drill stem is eliminated from the bit, i. e., it is prevented from being transferred to the bit. Accordingly the invention comprises a device for attaching the cutting tool to the rotary drill stem which is so constructed as to transmit to the bit the rotation of the drill stem but at the same time permit the axis of the drill stem to deviate from the axis of the bit itself, or, in other words, from a line ]ieipr-\,iuliriil:\r to the surface being cut.

My invention will be better understood by referring to the accompanying drawings which illustrate by way of example, several embodiments of the invention. In these drawings Fig. l is a vertical section of the lower end of a hole illustrating the general principles of the invention;

Fig. 2 is a vertical section through the u'niversal joint type of bit seating device which I now consider to be best adapted to carry out the invention;

Fig, 3 is a horizontal section taken on the line Q-Q of Fig. 2;

Fig. 4 is a vertical section of a modified form of bit seatingr device;

Fig. 5 is a bottom view of a device similar to the one shown in Fig. 4, but in which the bit is made in sections;

Fig. 6 is a. vertical section taken on the line 6 6 of Fig. 5 illustrating the manner ot mounting the sections; and

Fig. 7 is a radial section taken on line 7 7 of Fig. 5.

Referring now to the accompanying drawings, and particularly to Fig. l. in order that the general principles of the invention may be more fully understood, the axis of the hole 10 which has been drilled by the tool or bit 11 is indicated by the line A. Line A is also the axis of the bit 11 which is perpendicular to the bottom 12 of the hole. The bit 11 is connected to the drill stem 13 by means of a universal joint 14 having its center of movement at the point V15.

The bit 11 is rotated through its connection with the rotary drill stem 13 by means of the universal joint 14e, but the construction of this joint permits the drill stem 13 to lean against the walls of the hole 10 for lateral support. p ment or guide 18 at the lower end of the drill f stem is in contact with the wall of the hole at the point 16, and a drill stem 13 would also be shown in contact with the wall if Fig. 1 were extended upwardly a short distance. The purpose of the enlargement or guide 13 will ,be explainedbelow. The movement of As indicated in Fig. 1 an enlarge- Y the drill stem 13 is not one of .pure rotation but is a combined rotation about its own axis B and oscillation about the axis of the hole A, the axis B generating a long slender inverted cone the axis of which is the axis A of the hole.

The freedom of movement of the universal joint 14 which constitutes the attaching device, or self-seating device, of my present invention is sutlicient to allow the drill stem 13 to obtain lateral support by leaning into contact with the walls of the hole, without transmitting the effect of this oscillation to the bit 11. The bit 11 therefore rotates smoothly with its entire cutting surface at all times in even contact with the bottom 12 of the hole, and without any tendency to chatter. 'lhe feeding pressure is substantially uniform over the entire area ofthe bit instead of being increased at the right hand rim or edge 1i' as would be the case if the bit were rigidly secured to the drill stem. There is no tendency for theV bit to cant to one side, raising the portion of its surface opposite the edge 17 out of contact with the bottom of the hole.

It is stated above that the axis B of the drill stem generates an inverted cone about the axis A of the hole. rThe maximum angle of deviation of the axis B, i. e. the angle at the point of the cone, will determine the degree of freedom of motion to be provided by the universal oint, 14.

In drilling through hard formations, for which the present invention is primarily intended, although the rubbing of the sides of the bit produces a slight enlargement o f the hole. there is no essential wear on the walls of the hole once the bit has passed. ln practice that portion of the drill stem iii-unediately above the universal joint which is re terred to above as the enlargement 13 should be nearly the same diameter as the bit. This enlargement tends tofact as a guide and prevent excessive leaning of the drill pipe which produces some tendency for the hole to deviate from a straight line. Above this enlargement thedrill stem is hushed down to its normal diameter which is usually about one-half the diameter of the hole.

Turning now to Figs. Z to Z inclusive of the accompanying drawings, we will examine the construction of the self-seating device. ln the form of self-seating device shown in Figs. Q and 3, the upper or driving member 18 is threaded internally at 19 to the lower end of the drill stem or drive pipe 13. Member 18 telescopes within an outer or driven n'ieinber 20, the iit between these two members being relatively loose as indicated by the space 21 since it is by the presence 'of this space that the lateral freedom of movement between the members 18 and 20 is allowed. The cutting tool or bit Q2, which in this instance is a steel bit having cutters secured tirmly to what is in eifect the lower lila lib

lon

vle

endl' of thedriven member' 20, this lower end being of a composite or built-upconstrnction for a purpose*which'will appear later. f L

`'l`heinner member18 is provided .on` its 'exterior about mid-way betweenits ends .with

ber 20. Aside from' the keys 27 the interior` et the driven memberQ() is bored outv as may beenseen at 28, from its bottom upwardly tothe taperinglshoulders 29. This bore is to receive the .enlargement and it' will be seen by reifer-ring to Fig. 2 that `the space 'continued downwardly between bore 28iandenlargement 25 for the same -purpos et ilnoviding freedom of movement-between the outer and inner members ofI the joint'. Spaces 8O are also providedon both sides of both keys 27,- between the keys and the sides of the key-ways 26. for the same purpose. The sloping shoulder 31 and the upper end of enlargement 25 coactwith the sloping shoulder 29 toprevent the outer member 2O from becoming disengaged from member 18. i v f e The lower end of member 18 tnrneddown to torni a shoulder 82 against which is fitted spherical surface corres aondino" to suriface 84. is provided on'the outerdriven member 2O:` pluralityof balls 86 which are preferably held in placeby the-usual retainer (not shown) are provided"between the bearing rings 88 and for, thev purposeof transmitting'the feeding pressure from the inember 18 tothe member 2O with the smallesty possible amount of iirictioin Bearing ring 85 isfretained within the bore '3281 by means 'of a-'collar 38 which is internally threfnhed at 8?' into the loweren'd ofinember 20. '7 The drilling-Huid passes downwardly through the drillpipe and the interiors `oi? meinbers-'18 andQO to the aperturesBQ provided propriatelygnide the Vtool and prevent the .a shoulder 43 in the upper end oi. i

hole vfrom deviating froinja substantiallystraight line. f; n l 1 f y The spherical. surfaces otbearing rings 88 and 85 have a common cent-eratl ai point'll which'is near the top of the outer member 2Ot and by mea-ns of thefpivotal bearingithus formed, and the loosey tit alla-round between the variousvparts of members 181 andj20,-the drill ste-1n 18 will be permitted-a limited freeH dem ofmovelnent and the device will operate as previously Adescribed in connection with 'lnasmuch as the space 21 allowed between the members 18 and 2O is snfiicient to permit the passage of a considerablev amount otl vdrilling` fluid, it is necessary tovk provide packing between the two members to resist this lea agey and compel the lluid toiiow the bit.

"ll he packing consists of a ring l2 of resilient material such as rubber which'is fitted against niber() and held in place by a threaded holding ring les lt will be noticed that.ringl-Zy isplaced opposite the center of oscillation 41 and the reason for thisl is to nrther reduce the "frietion between the two members of the joint by placing the packing where not only the mini mum amount of motionybnt also the simplest l motion between' the twok members takes place.

The lvertical dotted lines proceeding from point 4:1 indicate the degree and direction of 'bemevement 'of the airis of the member 18 ith respect to the axis'o'f .in-einher Q0. and the horizontal dotted linesproceeding?` troni point Lllfindicate the .extent ot 'the' relative vertical movement between the opposite -.f faces ofthe two members which takes place ,as thelres'nlt Ioi' the first n'iovement. n

The resilient packing .ring 'fllds held ii'rn'ilv in place by shoulde idf-zand bindingiring but these parts are'purposely const usted tof cansenringAQ to? project; inwarf'llvior a, sub- .ntial distance 45 where the' rii ported at its sides. This allows the mater oi the ring l2 lio-yield s'ln'iicientlj,Y in the tical direction tor/take nup' the mo-veinentn cated by the'dotted vlinesentirely by tb siliency or give in the material itsel is unsnw y without,anyrslippage of the i *terior sin-,races of ring 4:2 on thesnrtace'ot member 18. lli this construction the friction between' parts 18 and has been ifonnd'to be reduecd'Vn a negligible amountso "1 reduced tothis extent there is subst no tendency for the ose-illationot the idrill stem to be transmitted-to* y bit and ce' a tendency to' chattering.r

VAlthough the bit'ZQ. whichhas been shown nti s l l v that wim ythe friet, i f

tratedfinrFig. 2v is ay steel bit which is intended n f lar' hole so as to enable "the v"taking of-acore,

and that the device is also advantageous when treating with either solid or annular bits constructed of abrasive material.

Referring now to the Inodiiication shown in F ig. 4, the cutting tool or drilling bit here consists of an annular ring 46 of abrasive materia-l, such for example as carborundum. This bit is therefore intended to cut an annular hole for the purpose of taking cores. The annular shank of the bit 46 is leaded into a metallic bit mounting 4'? and this mounting is received within the lower end of an annular recess 48 formed in the bottom of a tool holder 49. The bit mounting 47 has an outer annular shoulder 47 at its upper corner, and the mounting is removably held within recess 48 by means of a plurality of pins 48 which are threaded through the outer wall of recess 48 and engage the shoulder. Tool holder 49 is a relatively massive annular steel casting which supports the various parts of the' tool and by which the tool is secured to the drill stem. For this latter purpose. tool holder 49 is reduced at its upper end and threaded at 50. f

Bit mounting 47 is provided with a series of guide rods 51 which are received within apertures 52 extending upwardly from the roof of recess 48. Bit mounting 47 and rods 51 slide freely in recess 48 and apertures 52 respectively, sutiicient clearances being allowed to permit the axis of the bit 46 to cant slightly with respect to the axis of the tool holder 49. Springs 53, however,are provided on the pins 51 which tend to maintain the bit 46 in its extended position. When the tool holder 49 is attached to the end of the drill stem the iiexible mounting of the bit 46 just described permits the drill stem to remain against the side of the hole without tilting or I ranting the bit 46; the rods 51 however transmit the rotation of the vdrill stem from the holder 49 to the bit. In this construction, however, the degree ot friction is greater than with the universal joint shown in Fig. Q.

In the modifications shown in Figs. 5.y 6 and 7 an abrasive bit is also employed but it consists of a plurality ofl separate sections 54 of carborundinn, or other suitable material. These sections are in dependentlj.T mounted in a bit holder 55.v which is in general similar to `that shown in Fig. 4.. The bottoni of bit mounting 55. however,r is provided with a plurality of radial slots 56 extending from the outer `surface of theV bit mounting inwardly and terminating short of the inner surface thereof. There is one slot for each carborundum section 54. The side walls 57 of these slots are tapering and therefore the slots are 'i Wedgeshaped, and theslots have shoulders sections 54 by means-of the dove-tail const-ruction shown in Fig. 6, and the mountings have guide rods 60 over which springs 61 are placed, and the rods 60 are received in radial slots 60 as indicated in Fig. 7. The purpose of the guide rod 60 is to act as a support for the spring 61 and to assist the bit mounting 59 in maintaining the bottom surface of the bit in flat position on the surface being cut.

The bit sections are assembled in the holder by sliding the bit mountings laterally into the slots 56, the rods entering the slots 60. V7 hen the bit mountings are all in place in the several slots a collar 62 which is threaded upon the exterior of the mounting 55 is screwed downwardly to cover the slots 56 and hold the bit mountings therewithin.

I claim:

1. A self-seating device for earth-boring bits comprising a pair of telescoping driving and driven members, means for imparting rotation from one member to the other, and having coacting angularly disposed feeding pressure transmitting surfaces, said members tting loosely together so as to permit a limited relative oscillation on said surfaces, and a packing ring mounted between said membersto prevent the escape of drilling fluid Yfromthe interior of the inner member, said packing ring being composed of yielding material and supported on one of said members with its sides free to move longitudinally with respect to the members so that the relative longitudinal movement between the members is taken up by flexing of the material of the ring.

2. A self-seating device for earth-boring bits comprising a pair of telescoping driving and driven members.. means for imparting rotation from one member to'V the other, and having coacting angularly disposed feeding pressure transmitting surfaces corresponding to tangents of arcs of the relative pivoted mo tions of the said surfaces, said members titting loosely together so as to permit a limited relative oscillation on said angularly disposed surfaces, and a packing ring mounted between said members to prevent the escape of drilling fluid from the interior of the inner member, said packing Aring being composed of yielding material and supported on one of said members with its sides free to move longitudinally with respectV to the members so that the relative longitudinal movement between the members is taken up by flexing of the material of the ring.

3. A. self-seating device for eartlrboring bits comprising a pair of telescoping driving and driven members, the driving member be'- disposed within the driven member and provided at its lower part with a cylindrical enlargement, the outer member having an enlarged bore at its lower end for receiving said enlargement, a key-way extending longitudinally of said enlargement and a key coacting therewith projecting inwardly from said bore, a pair of coacting feeding pressure transmitting surfaces mounted on said respective members, and means for securing a drilling bit to the outer' member.

l-qAself-seating kdevice for well drilling bits coinpi'isiinga pair of telescoping driving and driven members, the driving member being mounted within the driven member', means for transmitting rotation between said members, a pair of coacting angularly disposed feeding pressure transmitting surfaces mounted on said respective members, and a skirt mounted at the lower end of thedriving member projecting downwardly below said coa-cting surfaces for directing the drilling fluid vpast said surfaces.r

5. In an earth drilling apparatus, a rotary drill stem, a drilling tool, and a universal iointfor securing the tool to the' drill stem, said vjoint comprising driving and driven members keyed to one another in snch'a inanner as to permit relative, limited motion between the parte, and said driving and driven members being provided with coacting angularly disposed annular surfaces` for transmitting feeding pressure from the said drill stem to the said drilling tool.

G. in an earth drilling apparatus, a rotary drill stein, a drilling tool, and a universal joint for securing the tool to the drill stein, said joint comprising driving and driven members keyed to one another in such. a manner as to permit relative, limited motion be-` tween the parts,said driving and driven members being provided with coacting angulai'ly disposed annular surfaces for transmitting feeding pressure from the said drill stem to the said drilling: tool, and Aallowing theaxis of the drill stem to deviate from the axis ofthe hole. Y

7. A self-seating device for earth-boring bits comprising a pair of-telescoping driving and driven members, means for imparting rotation'from one member to the other,fsaid` members fittinoloosel tooether so as to )erinit a limited relative oscillation of the driving and `driven members,and packing 1 eans between said 'telescoping members for venting the escape of drilling fluid from'the i interior of the inner member.

` end, means for imparting rotation from the driving member to the driven member, means for transmitting feeding pressure from the driving to the driven member` at a point relatively near the bit to prevent disalignment of the hole being bored, said members fitting loosely together so as to permit a limited relative oscillation of the driving vand driven members, and packing means between said telescoping'members for preventing the escapeofdrilling fluid from the interior of the i inner fmember. i l 9. An earth drilling apparatus for deep well drilling comprising a rotary drilling bit,

an elongated Vcylindrical bit carrying member closely fitting the hole being drilled 'and of sufiieientlength to properly guide the bit as it advances, a rotary drive shaft smaller than the hole being drilled and extending through-I out thedrilled portion thereof, and mecha-Y sufficient length to properly guide the bit: as l it advances, a flexible drive shaft smaller than the hole Vbeing drilled yand extending throughout the drilled portion :ther-cof, and

Vmechanism for operatively connecting said bit-carrying member to said drive shaft to turn 'said member and apply feeding pressure thereto, said mechanism including n'ieans for permitting the axis of the bit to move angularly with respect toi the axisof the drive shaftso as to allow the drilling bit to remain seated upon the surface beingcut when thek axis of the drive shaft diverges rom the of thehole, and also' including means for applyingsaid feeding'fpres'sure at a point close to the lower end of said bit carrying member thereby applying-feeding pressure without influencing the bit Vcarrying member to deviate from drillinga straight hole.

" vv11. An earth drilling apparatus for deep well drilling comprising a rotary Adrilling bit,

an elongated cylindrical bit'carrying member closely 'fitting the `-hole being drilled and of sufficient length to properly guide the bit as it eos,

for deepk I advances, a flexible drive shaft smaller thanv v the holeibeing drilled'and extending throughout the drilledv portion thereof, a driving u member attached to said Vdrive shaft and tele- Ascoped.loosely into said bit carrying member so as to permit the axis ofthe bit'to move angularly with respect to the axis of the drive shaft to allow the drilling bit to remain seatedupon thev surface being cut when the ofthe drive shaft diverges from the axis of the hole, said driving membercoacting with the bit carrying member to turn the same and having a bearing near the bottom of said bit carrying member for transmitting longitudinal feeding pressure from the driving member rto the bit carrying member thereby applying feeding jpressure without influencing the bit carrying member from drilling a straight hole.

l2. An earth dri-lling apparatus for deep well drilling comprising a rotary drilling bit, an elongated cylindrical bit carrying member closely fitting the hole being drilled and of sufii'cient length to properly guide the bit n as it advances, a flexible drive shaft smaller than the hole being drilled and extending throughout the drilled portion thereof, a hollow driving member attached to said drive shaft and telescoped loosely into said bit carrying member thereby permitting the axis of the bit to move angularly with respect to the axis of the drive shaft so as to allow the drilling bit to remain seated upon the surface being cut when the axis of the drive shaft diverges from the axis of the hole, said driving member coactingl with the bit carrying member to turn the same, and a flexible packing between said drive member and said bit carrying member to confine drilling fluid therein.

13. An earth drilling apparatus for deep welldrilling comprising a rotary drilling bit, an elongated cylindrical bit carrying member closely fitting the hole being drilled and of suiiicient length to properly guide the bit as it advances, a flexible drive shaft smaller than the hole being drilled and extending throughout the drilled portion thereof, a driving member attached to said shaft and telescoped loosely into said bit carrying member, thereby permitting the axis of the bit to move angularly with respect to the axis of the drive shaft so as to allow the drilling bit to remain seated upon the surface being cut when the axis of the drive shaft diverges from the axis of the hole, said driving member coacting with the bit carrying member yto turn the same, and a bearing near the bottom of said bit `carrying member for transmitting longitudinal feeding pressure Ato said member from the driving member, said bearing having coacting surfaces shaped to permit lateral movement of said surfaces with respect to each other so as to permit said angular movement of the bit cari.' ing member to take place.

la. An earth drilling apparatus for deep well drilling comprising a rotary drilling bit, an elongated cylindrical bit lcarrying member cl ly fitting the hole being drilled and of suin nt length. to properly guide the bit as it advances, a flexible drive shaft smaller than the hole being drilled and extending throughout the drilled portion thereof, a driving member attached to said shaft and telescoped loosely into said bit carrying member, 'thereby permitting the axis of the bit to move singularly with respect to the axisof the drive shaft so as to allow the drilling bit to remain seated upon the surface being cut when the axis of the drive shaft diverges from the axis of the hole, said driving member coacting with the bit carrying member to turn the same, and a bearing near the bottom of said bit carrying member for transmitting longitudinal feeding pressure 'to said member from the driving member, said bearing having curved coacting surfaces the center of curvature of which lies on the axis of the bit carrying member ata point near the top thereof.

l5. An earth drilling apparatus for deep well drilling comprising a rotary drilling bit, an elongated cylindrical bit carrying member closely fitting the hole being drilled and of suficient length toproperly guide the bit as it advances, a flexible drive shaft smaller than the hole being drilled and extending throughout 'fhe drilled portion thereof, a driving member attached to said shaft and telescoped loosely into vsaid bit carrying member, thereby permitting the axis of the bit to move ang-ularly with respect to the axis of the drive shaft so as to allow the drilling bit to remain seated upon the surface being cut when the axis of the drive shaft diverges from the axis of the hole, said driving member coacting with the bitV carrying member to turn the same, and a bearing near the bottom of said bit carrying member for transmitting longitudinal feeding pressurer to said member from the driving member, said bearing having coacting curved surfaces lhe center of curvature of which lies EGGLESTON SMlTI-l. 

